The present invention relates to a new type of memory cell, and more particularly relates to a superconducting magnetic memory cell.
Since the recent discovery of high temperature superconducting oxide ceramics, many peculiar characteristics of the ceramics have been found. Many of them are disadvantageous rather than advantageous. For example, when sintered, the ceramic structure includes a large amount of cracks and gaps which may obstruct superconducting currents. So far, it has been considered desirable to avoid such cracks and gaps.
On the other hand, Josephson devices are representative superconducting memory devices. The memory of this type is considered promising due to its high response speed. It is very difficult however, to form, within a ceramic oxide superconductor, Josephson junctions of the order of several hundreds of micrometers in thickness because in order to make the ceramic superconducting, the ceramic material has to be fired at a high temperature, in which case the ceramic material tends to react with other materials (consisting of the junctions ) at such a high temperature.